Such foot pedals are well known from the state of the art, for example from the U.S. Pat. No. 7,439,462, and are intended to provide a treating physician during treatment with a room for maneuver that allows him to continue treatment without interrupting it for manual modifications to the medical device. Instead of interrupting the treatment, he makes modifications to the medical device using the foot pedal. Essential components of the foot pedal are a housing with a housing base and a cover element which is height-adjustable in relation to the housing base along an actuating direction and which is usually also inclinably or tiltably mounted. Typically, the cover element rests on an actuating device arranged centrally below the cover element and displaceable along the actuating direction, so that the cover element can also be tilted to either side (see DE 20 2006 015 718 U1). Here the actuating device serves as a lever point or lever surface.
In order to induce different functionalities on the medical device with the foot, it is desirable that stepping on the edge area of the cover element is assigned to a first functionality of the medical device and a stepping on a central area of the cover element is assigned to a second functionality of the medical device different from the first functionality. In order to be able to distinguish between these two types of actuation, the actuating device is mounted in a height-adjustable manner, wherein the height offset of the actuating device is caused both when stepping on the edge area and when stepping on the central area. The height offset of the actuating device when stepping on the edge area is supported by the fact that during tilting the movement of the cover element on the side opposite to the actuated edge area is limited upwards, i.e. in a direction opposite to the direction of actuation.
Assuming the same force size, however, a force acting on the edge area leads to a smaller height offset of the actuating device than a central force acting on the cover element, in particular directly above the actuating device usually located in the central area. Accordingly, a differentiation can be determined on the basis of the respective size of the height offset. Therefore, in the U.S. Pat. No. 7,439,462, a first switch for initiating a first functionality of the medical device and a second switch for initiating a second functionality of the medical device are configured such that the first switch in a first height offset section and the second switch in a second height offset sections following the first height offset portion can be operated one after the other by the actuating means moving in the direction of actuation.
However, this does not prevent a user of the foot pedal from exerting so much force when actuating the cover element at the edge that the actuating device imperceptibly reaches the second height offset section and thus inadvertently triggers the second functionality.